Premia exploit: 191.8 ETH turned into 5.27 BTC within an hour, and 4 BTC of it was deposited to HitBTC the same morning

Premia is an options protocol; its v3 “underwriter vaults” put depositors’ collateral to work selling options through option pools. On 1 November 2026 six of those vaults on Arbitrum (WBTC, WETH and ARB, calls and puts) lost most of the collateral they held directly. Blockaid described the method: the attacker created empty option pools, used flash loans to buy options so that vault collateral was locked into those pools, then withdrew that collateral as pool liquidity — the vaults trusted any newly created pool. Loss estimates range from about $400,500 (Blockaid, during the attack) and $437,000 (The Defiant) to $464,600 (PeckShield). Premia had not published a post-mortem when this was written. PeckShield reported that the stolen funds moved to Ethereum and were swapped into bitcoin through Chainflip and NEAR Intents.

The attacker wallet 0xbeBa8CEfD0D75d747C5AD966Dc17C0Bb60D84dBd got its Arbitrum gas at 01:28 UTC through MetaMask’s bridge, deployed its exploit contract 0x577168c8c6fa937495c3d6961f1d7d734b2d785f at 03:14:36 and called it at 03:14:37. One minute later, at 03:15:39 and 03:15:40, the contract paid the wallet 43.24 ETH and 148.54 ETH: 191.78 ETH in total. The WBTC and ARB taken from the vaults had already been turned into ETH inside the contract; the wallet never held anything else of size.

From 03:18 to 03:31 UTC the wallet sent the 191.78 ETH on Arbitrum to nine addresses in round amounts. 30 ETH went to two Chainflip deposit channels and came out as bitcoin. 20 ETH went to a NEAR Intents deposit address and also came out as bitcoin. 131.82 ETH went to six more NEAR Intents deposit addresses with the instruction to deliver ETH on Ethereum — to the same wallet; NEAR Intents’ hot wallet 0x2CfF890f0378a11913B6129B2E97417a2c302680 paid it 131.57 ETH there between 03:26 and 03:31. The last 10 ETH went to a deposit address of a cross-chain service whose sweeper contract swapped it into 22,639.78 USDC and burned that through Circle’s CCTP for Solana, where it was minted at 03:19:29 and forwarded thirteen seconds later to a Solana wallet JEJGkbBaoas7soCcTXK67q9VZ9rg3wJWSLEfj83ZgZi9 that makes hundreds of transactions a day — a service’s wallet, not one the attacker controls.

On Ethereum, from 03:32 to 03:44 UTC, the 131.5 ETH went out in five round amounts: 81.5 ETH to three Chainflip deposit channels (0x7Dd0f781655a628AcEB44ce07f2F5e9a641E048A, 0x23eb7AEEA82cbF9CB37fD16420a1074ba1073125, 0x53DF77e44a66212E7BC674354c7ED0bCA1871918, all forwarding to Chainflip’s vault 0xF5e10380213880111522dd0efD3dbb45b9F62Bcc) and 50 ETH to two NEAR Intents deposit addresses. Both services publish the status of a swap: Chainflip’s swap API and NEAR Intents’ 1Click API return the destination asset and address for each deposit. All eight that took the money to bitcoin did so — five through Chainflip for 3.2317 BTC, three through NEAR Intents for 2.0363 BTC — each to a fresh bc1q address. Every Chainflip swap went through the same broker account, charging 0.3%.

The eight payouts arrived between 03:25 and 04:15 UTC. Each was spent once the same day, almost always into a round piece plus change: 1.0 or 0.5 BTC to a new address, the remainder to a change address that was later combined with other change. Six of the round pieces — two of 1.0 BTC and four of 0.5 BTC, 4.0 BTC in all — went to addresses that never spent on their own. At 09:29 UTC all six were swept together with 523 other inputs into one 27.35 BTC transaction to bc1qdfl3dfnwwvlqa5jpckh0ccwpjczh5y566c4g76, a hot wallet of the exchange HitBTC. That is how an exchange collects its customers’ deposit addresses: the six are HitBTC deposit addresses, and the 4.0 BTC was credited to one or more HitBTC accounts that morning.

About 1.1 BTC more left in three swaps marked with an OP_RETURN memo beginning “=|lifi”, the tag LI.FI’s routing adds to bitcoin deposits; about 1 BTC (0.5 BTC to bc1qkvwph7r683m7qkrz09k7p369a8lyk4q58200ca, 0.35 BTC to bc1q09dez4x32zp27jhg6xffxwdc0mxx07pjxvd0l8 and two small taproot outputs) is not yet traced. On 4 November the attacker sent 0.09 ETH from the emptied Ethereum wallet through THORChain to 0xfa3C17e19F433Cc13820C930957428288250Da17 on Base, which is gas money for a next step there.

Some early summaries said the attacker swapped the funds into SOL, that Mayan and Relay froze about $280,000, and that 251 ETH remained unmoved on an Ethereum address. In this attacker wallet’s flows on Arbitrum and Ethereum we found no SOL swap other than the 10 ETH USDC leg described above, no transfer through Mayan or Relay, and no wallet left holding ETH: by 03:44 UTC on 1 November the wallet held 0.07 ETH of gas. If a freeze happened, it was not on this path.

It does not say who the attacker is, or that Premia, Chainflip, NEAR Intents, Circle, LI.FI, THORChain or HitBTC did anything wrong: the swap services executed valid deposits, and an exchange cannot see what arrives at a deposit address before it is credited. It does not describe the vault flaw beyond what Blockaid has published. The loss range is Blockaid’s, The Defiant’s and PeckShield’s; the routes, swap destinations, bitcoin peel, HitBTC sweep and balances are PublicAML’s own reading of the chain on 7 November 2026. The HitBTC account behind the six deposits is the one lead that ends at an institution able to identify a customer.